FR3054298A1 - VEHICLE LIGHT PROJECTOR - Google Patents

Abstract

The invention particularly relates to a vehicle light projector (20) comprising at least one housing (22), at least one light source support (16-18) located inside the housing, a system adjusting the position of the light source relative to the vehicle, and a heat dissipation system (24,25-28) from the inside (43) of the housing to the outside (49) of the housing. The invention thus provides an improved light projector.

Description

FIELD OF THE INVENTION

The invention relates to the field of vehicle light projectors, that is to say devices making it possible, when driving the vehicle, to project light illuminating the road and / or allowing the vehicle to reach more visible, such as position lights or low beam and / or high beam (commonly called "headlights").

BACKGROUND

Vehicle light projectors include a housing integrating various components, including, when using the projector, a light source. At least part of the various components generate heat during their use, which causes an increase in temperature at the level of the components which can degrade the components and / or prevent their optimal use. Different solutions try to remedy this problem. This is the case, for example, for the solutions described in document US 2011 310 631 A, in document US 2006076572 A, in document US 20100296308 A, in document DE 102011120123 Al, in document US 2015 168 555 A, in document CN 103807719 A, or in document CN 203823623 U.

The aforementioned solutions are however not optimal, in particular with regard to the evolution of the performance of modern projectors and the amount of heat that their components generate, and the heat around the components inside the housing is therefore not sufficient dissipated.

SUMMARY OF THE INVENTION

A vehicle light projector is therefore proposed comprising at least one housing, at least one light source support located inside the housing, a system for adjusting the position of the light source relative to the vehicle, and a system for heat dissipation, from the inside of the case to the outside of the case.

According to different embodiments, the projector can include one or more of the following characteristics combined together:

the heat removal system includes a flexible heat communication system;

the heat removal system comprises at least one fluid heat exchanger and a heat communication system connecting the light source support and the fluid heat exchanger;

the fluid heat exchanger is a liquid heat exchanger;

the fluid heat exchanger comprises a system for connection to a cooling circuit;

the cooling system is a low temperature vehicle cooling loop;

the fluid heat exchanger includes a cold plate; the cold plate is located outside the housing or forms a wall of the housing;

the fluid heat exchanger is fixed relative to the vehicle, the heat communication system being flexible; the fluid heat exchanger is fixed relative to the light source support, the heat communication system being flexible or rigid;

the heat communication system comprises a heat pipe and / or a fluid circulation circuit; and / or the projector comprises two light source supports, the light source supports both being located inside the same housing or each inside a respective housing, and / or the projector comprising an exchanger of fluid heat common to the two light source supports or a respective fluid heat exchanger for each light source support.

BRIEF DESCRIPTION OF THE FIGURES

Other characteristics and advantages of the invention will appear on reading the following detailed description of the invention, given by way of example and with reference to the appended drawings, in which:

FIG. 1 schematically shows an example of the light source support with a light source mounted on the support; and FIGS. 2-5 schematically show different examples of the projector.

DETAILED DESCRIPTION

A vehicle light projector is proposed, as well as a land vehicle integrating one or more versions of such a projector (for example two versions at the front for a four-wheeled vehicle, or one or two versions at the front for a two or three wheel vehicle), for example according to one or more of the different integration methods described later. The projector comprises at least one housing and at least one light source support located inside the housing. The projector can therefore further comprise such a light source, for example a light source mounted on each respective support, the light source support being suitable for mounting and the functional movement of a light source inside the housing to allow the lighting when using the projector (such mounting can be done at any time, for example in the factory and / or later). The headlamp furthermore comprises a system for adjusting the position of the light source relative to the vehicle (which implies that the position of the lighting is not definitively fixed at the factory and can therefore simply be modified later). In the case of several supports and therefore of several light sources, the projector comprises such an adjustment system for each support since the light source is designed to be adjustable in position relative to the vehicle, or else a common adjustment system for all these supports, the adjustment being able in both cases to be carried out independently or on the contrary in an interdependent manner (eg integrally) for all these light sources. The projector also includes a heat removal system from inside the housing to the outside of the housing.

Such a configuration with such a heat evacuation system allows, for a projector whose lighting is adjustable in position relative to the vehicle, efficient dissipation of the heat generated and present around the components when the projector is used. This reduces the degradation of the components inside the housing (including the light source support and the light source) and this allows optimal use of these components (given in particular that the light sources of vehicle light projectors provide lighting optimal when the temperature is relatively low).

The vehicle can be any type of land vehicle, for example an automobile, a motorcycle, or a truck. The headlamp includes fixing means, for example by fitting or embedding, in a zone of the vehicle provided for this purpose. The attachment means are adapted, in terms of size, mechanical characteristics, and / or rigidity of the attachment, to the type of motorized vehicle and / or to the speeds attainable by the vehicle. The area (or framework) of the vehicle intended to accommodate the headlight can form a carcass around the headlight protecting the headlight from the heat of the engine. The light projector has at least a non-opaque portion (which may include a lens) of the housing, in the sense that after such fixing, the light emitted by the light source can be projected towards the outside of the housing so as to provide road lighting while driving.

In addition, the light projector comprises a housing with means forming, at least after such fixing, an enclosure and including the interior of the housing and therefore the light source support (as well as the light source mounted on the support if necessary if applicable). For example, the light projector comprises a closed sealed wall, the interior of the housing thus forming the sealed enclosure by itself. In another example, the housing comprises an open sealed wall which can be connected in a sealed manner to a sealed surface of the area of the vehicle intended to accommodate the headlight (and geometrically complementary to the opening of the wall). In all cases, at least after fixing the projector, the interior of the housing defines a sealed volume outside, so that the components therein (such as the light source support and, where appropriate, the light source) are protected from the outside, especially from rain and / or impurities.

As indicated above, various solutions exist in the prior art for dissipating heat at the level of the components inside the housing which give off heat during their use, in particular the light source and its support. However, existing solutions mainly consist in evacuating the heat to a cooler area of the housing. However, the above-mentioned tightness causes the heat given off by the components to be confined inside the housing, even if this heat is transported to other zones of the housing. The heat accumulating in the housing can then become too high.

It is therefore proposed, in addition to or as a replacement for these solutions, that the projector comprises a heat evacuation system from the interior of the housing to the exterior of the housing. This evacuation system can be any system which evacuates the heat at least in part towards the outside of the case, such a heat flux being strictly greater (in terms of intensity) than the simple flux resulting from natural convection and from the heat exchange at the walls of the housing. Such an architecture of the projector therefore makes it possible to improve the dissipation of the heat generated by its components away from said components, and this at a lower cost in terms of hardware complexity and therefore of installation of the projector.

Furthermore, the light projector includes a system for adjusting the position of the light source relative to the vehicle. Such an adjustment system allows the horizontal and / or vertical adjustment of the light beam generated by a light source of the projector. The adjustment can be made by actuating different mechanical elements. For example, the projector adjustment system may include mechanical positioning elements connected to the supports of all the light sources adjustable in position. The housing can in this case be provided to be assembled to the vehicle in a fixed manner with respect to the vehicle, and the light sources can themselves be fixed (that is to say of non-adjustable position) each with respect to their support respective. The mechanical positioning elements can then be configured to adjust the position of the supports (independently or in an interdependent manner, for example integrally, that is to say that when the position of a support is changed the position of the other (s) ( s) support (s) integral (s) is modified by the same amount), so as to indirectly adjust the position of the light source and therefore the projected light beam.

However, the improvement in the heat dissipation proposed is all the more useful since the headlight includes such a system for adjusting the position of the light source relative to the vehicle.

The heat removal system may include a flexible heat communication system. The flexible heat communication system can be any element (eg defining a portion) of the heat removal system which has mechanical flexibility and which is configured to communicate heat over a distance. When the projector is mounted on the vehicle, the heat dissipation system can form a heat dissipation path from a point A inside the housing where it is generated (for example the light source support) to a point B outside the housing and fixed relative to the vehicle. Point B can for example (as will be discussed later) be a linked and fixed point with respect to a fluid heat exchanger, such as a liquid heat exchanger, itself fixed with respect to the vehicle and / or any mechanical element fixed relative to the vehicle, for example a vehicle cooling circuit (evacuation can then in this case be done via a fluid heat exchanger (as mentioned above) located for example on the heat removal path between point A and point B, the exchanger may in this case not be fixed - that is to say free, ie may move flexibly - relative to the vehicle). The flexibility of the heat communication system then allows the heat dissipation system not to hinder the freedom of movement of the light source (which is for example fixed relative to point A) relative to the vehicle, required for the adjustment. in position of the light source relative to the vehicle.

Such a flexible heat communication system can comprise at least part of a heat communication system which connects the light source support and the heat exchanger by fluid, for example by liquid (and discussed previously), for example a flexible heat pipe or a flexible fluid circulation circuit (for example liquid) (for example at least two flexible pipes). Alternatively or additionally, the flexible heat communication system can comprise at least part of a connection system (for example a heat exchanger) to a cooling circuit of the vehicle, for example a circulation circuit of fluid (eg liquid) flexible (eg at least two flexible hoses).

The headlamp may comprise a light source having a position light function, a light source having a low beam function, a light source having a high beam function, and / or one or more light source (s) ) having any combination of the above functions. In one example, the headlamp comprises a light source having a position light function and a light source having both a low beam function and a high beam function.

Indeed, these types of lights which require, in particular because of the laws, that a user can regulate them simply in position except factory (on the contrary for example fog lights, whose position is fixed in factory) have in their recent versions a relatively high number of electronic components concentrated in the same place (in particular close to the light source). In addition, their electronic components and their light source can be relatively powerful and therefore dissipate relatively high heat. Also, their light source can be particularly sensitive to ambient temperature for its proper functioning.

For example, the light projector can include inside the housing of the processing electronics, for example integrated into a module also integrating the support or integrated into the light source support itself. The processing electronics can have a code function, a road function and / or an anti-dazzle function when driving on the road. In addition or alternatively, the support can be configured for mounting one or more light source (s) consisting of a light-emitting diode system, and the support can be configured to operate at a energy density greater than 50mW / cm ² (for example of the order of 100mW / cm ² ). The heat evacuation system from the inside of the case to the outside of the case is therefore of particular use because it responds to the problem of heat concentration inside the case which is particularly troublesome in the specific context of a such a projector, where conventional cooling means (for example with radiator cooled by natural convection) are insufficient. Indeed, a problem in this context is that the confinement of the light source and the electronic components making it possible to ensure the multiple driving assistance road functions associated with basic signaling functions (position light, flashing by example) mean that the ambient air often exceeds temperatures of 80 ° C in extreme conditions of external temperatures for dissipated powers greater than 50W. However, to have an optimized optical flux, the temperature inside the housing should be as often as possible in the external temperature range between 35 ° C and 70 ° C. The heat evacuation system can be configured to ensure this, while respecting the specific constraints of the projector (ie adjustment in possible position, no dust, and no contamination of the external environment on the optical module).

In one example, the projector comprises an optical module which includes a wafer or semiconductor wafer, for example silicon, with one or more zone (s) configured to accommodate a light source, consisting of a or several light sources, of dimension greater than 1 mm ² , the plate also integrating an integrated circuit, for example an integrated circuit specific to an application (ASIC). The plate can be attached to a heat sink. The heat sink can be made of a material with high thermal conduction or a flat heat pipe. The assembly comprising the plate, the integrated circuit and the possible dissipator thus constitute one or more light source support (s).

FIG. 1 schematically shows an optical module 10 according to this example.

The optical module 10 comprises a light source 12 consisting of a three-dimensional (3D) diode system, a lens 14 which can optionally cooperate with the light source 12 to generate a light beam, a silicon plate comprising an area 16 configured to receive a light source (the zone 16 receiving the light source 12 in the example of the figure) and a zone 17 consisting of a conductive element which can optionally be provided with micro-heat pipes forming a heat sink. Micro-heat pipes are particularly effective in terms of heat dissipation. Zone 17 is equipped with micro-heat pipes or heat pipes which can be connected to form a circuit making it possible to communicate (ie conduct) the heat outside the support (for example by connecting to the heat communication (or conduction) system mentioned more late). Alternatively, the zone 17 could form a heat sink in another way, for example by means of an integrated liquid circuit, or even by natural convection. Such examples are simple to carry out. The plate also integrates the integrated circuit 18. The assembly 16-18 of the example thus forms a support configured for the mounting of a single light source on a mechanical plate accommodating the adjustment mechanics, but this mechanical plate can be adapted to accommodate several light sources, in a conventional manner.

Different examples of the projector are now discussed with reference to FIGS 2-5.

FIGS. 2-5 all show a different example of a vehicle light projector 20 as described above, and comprising at least one housing 22 (a single housing 22 in the example of FIGS. 2-3 and two separate housings 22 in the example of FIGS. 4-5) and integrating two optical modules 10 according to the example described with reference to FIG. 1 (an optical module 10 per box in the case of FIGS. 4-5). In all the examples shown by FIGS. 2-5, the heat removal system comprises at least one heat exchanger 26-28 per fluid (for example a heat exchanger by liquid or “liquid heat exchanger” of the cold plate type, with potentially a spread of heat by micro-pipeline and / or "radiator"). A fluid heat exchanger can constitute a system making it possible to transfer thermal energy from a solid by the circulation of a fluid to an exchanger. Such a cold plate connected to a heat exchanger allows good dissipation of the heat generated in the housing 22, and in particular a better heat evacuation than by convection (even forced).

In particular and as already indicated with reference to FIG. 1, each module 10 is equipped with a heat conducting element 17 configured to dissipate the heat generated by the module and / or spread it (as is well known in the field of power electronics). The conductive element 17 dissipating / spreading the heat is connected to a heat communication (or conduction) system 24 or 25 which brings this heat to the heat exchanger of the cold plate type 26-28. The heat communication system 24,25 thus connects the light source support 16-18 and the heat exchanger 26-28, so as to dissipate the heat generated and / or stored by the light source support 16-18 ( heat which is therefore inside 43 of the housing 22) towards the outside 49 of the housing. Indeed, as seen in FIGS. 2-5, the heat exchanger 26-28 is located outside 49 of the housing 22.

In the examples of the figures, the fluid heat exchanger comprises in particular a cold plate 26 (that is to say a plate which can be cooled by a cooling circuit, "cold plate" or "cooling plate" in English ). This well-known type of heat exchanger (eg liquid) is simple to produce and is particularly suitable, in terms of geometry and mechanical characteristics, for such an application for a vehicle light projector. The cold plate 26 is therefore located (at least partially, that is to say fully or partially) outside 49 of the housing 22, so as to make the heat dissipation particularly effective. In the example of FIGS. 2-3, the plate 26 is fixed against the bottom of the housing 22 (relative to the direction of the light beam). This configuration contributes to good mechanical rigidity of the assembly and a simple installation of the headlight 20, the plate 26 being able to be pre-assembled to the housing 22, the assembly then being fitted into the zone of the vehicle provided for this purpose. In this configuration, the plate 26 could alternately form a wall (e. G. Of the bottom) of the housing 22. In the example of FIGS. 4-5, the plate 26 is spaced from the bottom of the housing 22 by a distance 55, which bottom of the housing 22 is pressed against a corresponding support plate 54 of the vehicle. This configuration allows the formation of an air wall between the cold plate 26 and the housing and forming thermal insulator, thus reducing the thermal effect coming from the exterior 49 towards the housing 22.

In the examples of the figures, each heat exchanger further comprises a fluid inlet Y1 (for example liquid) and a fluid outlet 28 (for example liquid). This allows the heat exchanger to be connected to a cooling circuit (for example liquid). The fluid of the cooling circuit thus maintains the plate 26 of the exchanger at a low temperature, so as to continuously dissipate the heat inside the housing 22. In particular, in one example, the cooling circuit can be a circuit vehicle cooling, which makes the device simple to produce and optimizes resource management (rather than developing a dedicated circuit). Relative to conventional light projectors without such a heat removal system, the projector 20 of these examples only requires for its installation the additional operation of connecting the plate or plates 26 to the cooling circuit in question, by means of the system connection comprising the inlet (s) 27 and the outlet (s) 28 (which may be flexible, and / or connection system which may further comprise a fluid circulation circuit, for example flexible, for example pipes connected to the cooling circuit). Thus, the heat exchanger of the examples in the figures can be supplied by the low temperature (below 90 ° C.) or high temperature cooling loop, or even both depending on the needs of thermal regulation. A connection to the cooling circuit which constitutes the low temperature cooling loop of the vehicle (well known and generally present, in particular on all electric or hybrid vehicles) makes it possible to maintain the temperature of the fluid for example at a maximum temperature of approximately 45 ° C. .

The projector 20 of the examples therefore makes it possible to dissipate the heat outside the housing 22 by using for example the cooling loops already existing on the vehicle (FIGS. 4 and 5). The projector 20 being in a smaller volume, the interior 43 of the housing 22 is found at a homogeneous temperature. This makes it possible to limit the presence of a cold zone in the ice which can generate risks of condensation. Furthermore, the configuration of the examples also makes it possible to have a cooling circuit external to the housing 22, which limits the risk of generating pollution inside the projector 20, for example in the event of a leak. Repair is also made easier. By associating with an already existing cooling loop, the weight of the projector 20 is also reduced, while avoiding having an internal cooling system in the projector.

The housing 22 of the examples therefore contains several optical modules 10 (exactly two, one acting as a position light and the other acting as a dipped and / or driving light) linked to a liquid-cooled exchanger (cold plate). The fluid heat exchanger can be produced in a single assembly (that is to say with a single plate 26 to which all the optical modules are linked), as is the case in the example of FIGS. 2, 4 and 5, or alternatively in several subsets (that is to say with several plates 26, each module 10 being linked to a respective plate 26, each plate 26 having its respective inlet 27 and outlet 28), as this is the case in the example of FIG. 3. In cases 4 and 5 the modules do not require adjustment relative to each other in the case. The adjustment is carried out directly by the adjustment system external to the housing 22 in a conventional manner.

FIGS. 4 and 5 represent an example making it possible to further reduce the self-heating effect from one module to another. In this example, the modules 10 are defined as waterproof products with their own housing 22 and their own adjustment system assembled on a structure. Each of the modules 10 is connected as described above to a cold plate 26. The cold plate 26 is common to the modules in the examples. But there could be a cold plate 26 per module 10 and therefore per housing 22, as explained with reference to FIG. 3. Such a plate 26 individual to each module could be pressed against the bottom of the housing 22 (as in the example of FIG. 3 or remain at a distance 55 (between the plate 26 and the support plate 54).

In all the examples shown in the figures, the headlight is mounted on the vehicle thanks to mechanical elements 31 fixed relative to the carcass / frame 35 of the vehicle and to mechanical elements 33 (as well as the plate 54 in the examples of FIGS 4 and 5) adjustable in position relative to the carcass / frame 35 of the vehicle. The elements 33 belong to the system for adjusting the position of the light source relative to the vehicle, the other elements of which are not shown in the figures, for the sake of clarity. These other elements however imply in the examples a minimum of play (ie distance 37, shown in FIG. 2 only) between the supports 16-18 and the cold plate 26 (for example greater than 1 cm, for example of the order 2 cm). So in the examples of F1GS. 2-3, the modules 10 are adjustable in position relative to the vehicle inside their common housing 22, the common housing 22 itself being fixed (i.e. frozen) relative to the vehicle. On the contrary, in the examples of FIGS. 4-5, it is the respective boxes 22 to an individual module 10 which are adjustable in position relative to the vehicle, the respective module 10 to each box 22 being itself fixed relative to said respective box 22.

In all the examples shown in the figures, the heat exchanger (s) 26-28 is (are) fixed relative to the vehicle. Therefore, the heat communication system 24,25 shown can be flexible, which ensures the mobility of the supports 16-18. If, on the contrary, the heat exchanger was fixed relative to the light source support 16-18 (which can be an alternative to the examples in the figures), the heat communication system 24.25 shown could equally be flexible or rigid (the flexibility with respect to the vehicle can then, in the case of a rigid heat communication system, be provided by a flexible part of the system for connection to a cooling circuit of the vehicle, for example the inputs 27 and output 28 or elements connected to it, as explained above).

In the examples of FIGS. 2-4, the heat communication system comprises a heat pipe 24. This allows a particularly efficient communication / conduction of heat from each support 16-18 to the corresponding cold plate 26. In addition, the heat pipe 24 can easily be formed flexible and thus allow the adjustment in position of the support 16-18 (if necessary). In contrast to these examples, FIG. 5 presents the alternative (instead of using a heat pipe 24 connected to the cold plate) to produce a liquid exchanger 25-28 with double inlet: with a liquid circuit 25 for cooling each module and the external circuit 27-28 mentioned previously .

Claims (12)

1. Vehicle light projector (20) comprising at least one housing (22), at least one light source support (16-18) located inside the housing, a system for adjusting the position of the light source relative to the vehicle, and a heat evacuation system (24,25-28), from the interior (43) of the housing to the exterior (49) of the housing. 2. Projector according to claim 1, wherein the heat removal system (24,25-28) comprises a flexible heat communication system (24, 25). 3. Projector according to claim 1 or 2, wherein the heat removal system (24,25-28) comprises at least one heat exchanger (26-28) by fluid and a heat communication system (24, 25) connecting the light source support (16-18) and the fluid heat exchanger. 4. Projector according to claim 3, wherein the fluid heat exchanger (26-28) is a liquid heat exchanger. 5. Projector according to one of claims 3 or 4, wherein the fluid heat exchanger comprises a connection system (27-28) to a cooling circuit. 6. Projector according to claim 5, wherein the cooling circuit is a low temperature cooling loop of the vehicle. 7. Projector according to one of claims 3 to 6, wherein the fluid heat exchanger comprises a cold plate (26). 8. Projector according to claim 7, wherein the cold plate is located outside the housing or forms a wall of the housing. 9. Projector according to any one of claims 3 to 8, in which the fluid heat exchanger is fixed relative to the vehicle, the heat communication system being flexible. 10. Projector according to any one of claims 3 to 8, in which the fluid heat exchanger is fixed relative to the source support 10 luminous, the heat communication system being flexible or rigid. 11. Projector according to any one of claims 2 to 10, in which the heat communication system (24, 25) comprises a heat pipe (24) and / or a fluid circulation circuit (25). 12. Projector according to any one of claims 1 to 11, in which the projector comprises two light source supports, the light source supports being both located inside the same housing or each inside a '' a respective housing, the projector comprising a heat exchanger 20 by fluid common to the two light source supports or a respective fluid heat exchanger for each light source support. 1/2